Where can you find a browser with which you can forge a static GIF? I don't know of any, though of course you could forge it with a paint program (although you'd probably want to make sure it was the same number of bytes), but you wouldn't even have to bother, just capture and reuse the original or call and use it from their server as in this case. Nonetheless there are significant differences between using a static GIF and Flash. Just look at the code given in the article, how do you do all that with a GIF? Although it would be interesting (if non-trivial) to do so employing some sort of Steganography [petitcolas.net] with oft changing embedded character strings or even PGP.

The current problem is somewhat like the problems encountered with dynamic GIF code used by GoDaddy and some other registrars to prevent mass WHOIS mining, and that is a technique that was already long in use by some search engines to stop mass submissions. Problem is that those who don't play nice had already figured out ways to spoof it even before GoDaddy et al got around to employing it.

BTW, the samples that should display in the article are presently broken, the author of the article perhaps deserves at least a free domain name for waking up Veri$ign. -g